With the popularity of radio communications technologies and mobile phones, base stations are seen everywhere in cities and countryside. Base stations are generally categorized into macro base stations and pico base stations according to the distance between base stations. An area covered by a macro base station is called a macro-cell (Macro-cell) and an area covered by a pico base station is called a pico-cell (Pico-cell). For contiguous coverage, adjacent base stations may cover the cell edge of adjacent cells, and equivalent-power interference exists at the cell edge of the adjacent cells. In this case, call quality and data rates of user terminals in the edge area may be affected. According to a traditional method, interference performance is generally improved passively by using interference suppression, frequency orthogonalization, soft frequency multiplexing, or by adding a mobile phone smart antenna. Concerning an issue on effectively using the power of adjacent base stations, coordinated transmission between adjacent base stations is being more and more focused in the academic field and industry field.
In the current Third Generation Partnership Project (3rd Generation Partnership Project, 3GPP for short) standards, a heterogeneous network (Heterogeneous Network, HetNet for short) uses macro-cells to achieve contiguous and seamless coverage of an area, and uses pico-cell overlapped coverage at hot points. The pico-cells are directed to a large number of service traffic demands at the hot points, providing a high capacity to implement “distribution on demand” for system capacity.
However, in the prior art, because of limitations of backhaul (Backhaul) capability and synchronization requirements, each base station is not capable of implementing real-time joint transmission to achieve resource scheduling and interference management. Consequently, enhancement of the system capacity is limited.